Cinder trap



Feb. 29,1944. (3. H. TRUE 2,343,209

CINDER TRA'P I Filed April 8, 1941 2 Sheets-Sheet l INVENTOR. 67/4/2455/;1 7781/5,

Feb. 29; 1944.

C. H. TRUE CINDER TRAP Filed April 8, 1941 2 Sheets-Sheet 2 INVENTOR.C/MRLES f7. 7506. BY: c Q i Patented Feb. 29, 1944 UNITED STATES PATENTOFFICE CINDER TRAP Charles H. True, Chicago, Ill., assignor to TheSuperheater Company, New York, N. Y.

4 Claims.

The present invention relates to improvements in locomotive fireboxesand particularly to means for recovering unconsumed fuel particles andcinders from the combustion gases.

The invention contemplates provision of a cirrder trap locatedrearwardly of the back tube sheet of a fire tube boiler and extendingtransversely of the firebox in spaced relation above the arch andopening toward the rear of the fire box so as to disentrain unconsumedfuel particles and cinders from the combustion gases. The cinders andparticles are then returned to the firebox above the grate bar throughone or more conduits connected with the pocket and associated with anejector. A feature of the invention is that the cinder trap pocket isformed by plate means so arranged as to form a circulator placing theside water legs of the firebox in direct communication with each otherand with the water space above the crown sheet.

The invention will be best understood upon consideration of thefollowing detailed description of an illustrative embodiment thereofwhen read in conjunction with the accompanying drawings in which:

Fig. 1 is a longitudinal sectional view through a locomotive typefirebox embodying the present invention.

Fig. 2 is a transverse sectional view through the firebox on the line2--2 of Fig. 1.

The firebox shown in the drawings is bounded at its forward end by theback tube sheet I of a fire tube boiler and along its sides by the waterlegs I I. The inner walls of the water legs II are formed by the sidesheets I2 which merge into the crown sheet I3. Circulating tubes I4extend upwardly and rearwardly from the throat sheet I5 to the innerback sheet I6 and support refractory bricks I! to form the firebox arch.

At corresponding locations rearwardly of the back tube sheet I0,vertical slots or openings 20 (Fig. 1) are formed in the side sheets I2.The crown sheet I3 is also cut away to provide an opening or slot BIextending transversely of the fire box and communicating at each endwith the openings 29 in the side sheets l2. The openings 22 in the sidesheets I2 also have rearward extensions 22, the opening in each sidesheet being in the general form of a reversed L. A

trough-like conduit designated as a Whole by the numeral 23 has openends registering with the openings 20, 22 in the side sheets I2 and itsopen top communicates with the slot 2I in the crown sheet !3. Theconduit 23 thus forms a circulator placing the two side water legs I Iin direct communication with each other and with the water space abovethe crown sheet I3. The conduit 23 is formed by a plate 24 having aflange 25 connected to the crown sheet I3 along the rearward edge of theopening 2!. From the crown sheet I3 the plate 24 extends downwardly andthence rearwardly, is reversely bent and then extends forwardly to beattached by a flange 26 along the forward edge of the opening 2|. At itsside edges the plate member 25 is likewise provided with flanges 21 bymeans of which it is secured along the marginal edges of the openings20, 22 in the side sheets I2.

In addition to constituting a circulator conduit, the plate 24 forms apocket 28 opening toward the inner back sheet I6 so that uncon sumedfuel particles and cinders are disentrained from combustion gases thatswirl into the pocket 28 as they fiow over the rear end of the arch I!towards the fire tubes connected to the back tube sheet I0. Inasmuch asthe plate member 24 forming the pocket 28 also constitutes a circulatorconduit, the cinder pocket is water cooled. Pipes 30 lead from the sidesof the pocket 28 to convey the fuel particles to the firebox above thegrate 3|. As illustrated herein, a single pipe 32 connecting with thetwo pipes 30 leads into the firebox and is provided with an ejectornozzle 33 supplied with steam through a pipe 34 so that suction may becreated in the pipes 30 for drawing unconsumed particles and cindersfrom the pocket 28 and returning them to the fire.

What I claim is:

1. In a fire tube boiler having a firebox provided with an archextending upwardly and rearwardly intermediate the grate and the fireboxroof from a point adjacent the rear tube sheet of the boiler; platemeans attached transversely of the firebox to the firebox roof in aposition rearward of said tube sheet and extending downwardly and thencerearwardly in spaced relation above the firebox arch to form a pocketopening rearwardly to receive fuel particles carried by the combustiongases.

2. A firebox construction as recited in claim 1, said plate meansextending completely across the firebox to thereby form a pocketextending from side to side of the firebox above the arch.

3. A firebox construction as recited in claim 1, the plate means thatforms said pocket constituting a hollow conduit communicating with thewater space of the boiler.

4. In a fire tube boiler having a firebox provided with an archextending upwardly and rearwardly intermediate the grate and the fireboxroof from a point adjacent the rear tube sheet of the boiler; acirculator conduit extending transversely of the firebox above said archand connected at its ends to openings formed in the inner side sheetsfrom a point above the arch to said roof, said conduit having a open topcommunicating directly with an opening extending completely across thecrown sheet for placing the water less in direct communication with thewater space above the crown sheet and also with each other throughoutthe height of said openings in said side sheets, said conduit alsohaving a portion extending rearwardly from its lower end in spacedrelation intermediate said roof sheet and arch to form a water cooledcinder pocket.

CHARLES H. TRUE.

